1. Field of the Invention
The present invention relates to a hydraulic device having an actuator to drive, for example, control surfaces such as flaperon, ailerons, spoiler, elevators and rudders of aircraft, a hydraulic module to control supply of a working fluid for the actuator, and a fluid distributor unit to hydraulically communicate between the actuator and the hydraulic module.
2. Description of the Related Art
A conventional hydraulic device of this kind is disclosed in, for example, Japanese patent laying-open publication Tokkai 2001-165103 (corresponding to U.S. Pat. No. 6,435,205) and comprises a passage block formed with a columnar space in the central portion thereof and fluid passage portions formed inside of the passage block, an internal body received in the columnar space and formed on the circumferential surface of the internal body with channels connected to the fluid passage portions, an actuator attached to a lower surface of the passage block to drive a control surface of an aircraft, and a fluid-controlled valve as a hydraulic module attached to an upper surface of the passage block to control supply and discharge of a high-pressure fluid for the actuator through the fluid passage portions of the passage block and the channels of the internal body.
The fluid passage portions of the passage block comprise a first head-site and rod-site feed/exhaust passage portion formed in the passage block at the upper side of it, and a second head-site and rod-site feed/exhaust passage portion formed in the passage block at the lower side of it. The first head-site and rod-site feed/exhaust passage portions connect the channels of the internal body and the fluid-controlled valve to each other, and the second head-site and rod-site feed/exhaust passage portions connect the channels of the internal body and the actuator to each other.
The actuator comprises a casing extending back and forth and defining a cylinder chamber therein, a piston slidably received in the cylinder chamber and partitioning it into a head-site chamber and a rod-site chamber, and a piston rod integrally attached to the piston and passing through a front end wall of the casing. The head-site and rod-site chambers of the actuator are respectively connected on the lower surface of the passage block to a second head-site and rod-site feed/exhaust passage portions.
The above known conventional hydraulic device, however, encounters such a problem that the passage block becomes longer in an axial direction of the actuator and heavier as a length of the actuator becomes longer, because the connections between the second head-site and rod-site feed/exhaust passage portions of the passage block and the head-site and rod-site chambers of the actuator need to be arranged at each end portion of the cylinder chamber to supply and discharge the high-pressure fluid to and from the head-site and rod-site chambers so that the piston can move between one end and the other end of cylinder chamber.
It is, therefore, an object of the present invention to provide a hydraulic device which overcomes the foregoing drawbacks and can reduce the axial length and the weight of the passage block.
It is another object of the present invention to provide a hydraulic device which can be easily manufactured and reduce its manufacturing cost.